Neuroprotection in aortic arch surgery: A risk factor analysis

Introduction: This study was undertaken to identify pre- and perioperative risk factors influencing outcome after operations requiring hypothermic circulatory arrest (HCA) in a single center.

Methods: Between 11/99 and 03/06, 501 consecutive patients (median age 64 years (20–86)) underwent aortic arch surgery with moderate HCA (25±2°C) and additional selective cerebral perfusion (14°C) (SACP) at our institution for various indications. Statistical analysis including stepwise logistic regression was carried out to determine risk factors for 30-day-mortality as well as for temporary (TND) and permanent (PND) neurological dysfunction.

Results: Overall mortality was 11.6%. TND could be detected in 67 pts (13.4%), 48 (9.6%) had PND. Independent risk factors for mortality were: age (p=0.019, hazard ratio [HR] 1.029/y), AADA (p=0.002, odds ratio [OR] 2.37), re-operation (p=0.035, OR 1.88), emergency operation (p<0.001, OR 2.62), previous stroke (p=0.039, OR 2.37), peripheral vascular disease (p=0.029, OR 3.11), renal insufficiency (p=0.002, OR 2.55), additional coronary artery bypass grafting (p=0.033, OR 1.88) and cardiopulmonary bypass time (p<0.001, HR 1.101). TND was associated with age (p=0.039, HR 1.023/y), AADA (p=0.015, OR 1.91), emergency operation (p=0.003, OR 2.15), renal insufficiency (p=0.043, OR 1.82) and HCA-times (p=0.016, HR 1.014/min). PND is associated with age (p=0.038, OR 1.028), previous stroke (p=0.006, OR 3.11) and operation time (p<0.001, HR 1.005/min).

Conclusion: Mortality and PND are primarily influenced by preoperative patient related factors. SACP seems to be a sufficient tool for neuroprotection. Nevertheless, TND occurred with increasing HCA and SACP times, implicating that even the safety of this technique is limited.